Data terminal device capable of continuing to download encrypted content data and a license or reproduce encrypted content data with its casing in the form of a shell closed

ABSTRACT

A cellular phone in the form of a shell downloads and reproduces encrypted content data distributed from a distribution server. The cellular phone includes a detection unit detecting whether its casing in the form of the shell is open/closed. If with the cellular phone currently downloading or reproducing encrypted content data its casing in the form of the shell is closed, a controller controls a power supply unit to supply power required for completing the download process or the reproduction process. Thus if the casing is closed the cellular phone still can complete the download or reproduction process. Thus with the casing having been closed the cellular phone can download or reproduce data.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to data terminal devices used in datadistribution systems capable of protecting the copyright of copiedinformation.

2. Description of the Background Art

In recent years the Internet and other similar information communicationnetworks have advanced and a cellular phone or the like is used for apersonal terminal to allow the user to readily access networkinformation.

On such an information communication network a digital signal is used totransmit information. As such, if a user copies music, video data or thelike transmitted on such an information communication network asdescribed above, each individual user can copy such data almost free ofsignificant degradation in the quality of sound, image and the like.

Thus, if music data, image data or other similar creations in copyrightare transmitted on such an information communication network without anyappropriate approach taken to protect the copyright, the copyright ownermay have his/her right infringed significantly.

However, prioritizing copyright protection and preventing distributionof copyrighted data on a rapidly expanding digital informationcommunication work, is disadvantageous to copyright owners, whobasically can collect a predetermined copyright fee for copyingcopyrighted data.

In contrast, if digital data recorded in a recording medium, e.g., musicdata recorded in a normally sold compact disc (CD), is copied to amagneto-optical disk (such as an MD), it may be copied, as desired, aslong as the copied data is solely for personal use, although anindividual user who example digitally records data is required toindirectly pay as a bond to the copyright owner a predetermined portionof the price of the exact digital recording equipment, MD or any othersimilar media used by the user.

In addition, if music data in a digital signal is copied from a CD to anMD the information is digital data copied without significantdegradation and accordingly equipment is configured to prevent copyingmusic data from a recordable MD to another MD and thus protectcopyright.

As such, distributing music data, image data and other similar data tothe public on a digital information communication network is itself abehavior subject to a restriction attributed to a public transmissionright of a copyright owner and a sufficient approach is accordinglyrequired for protection of copyright.

Conventional cellular phones have a casing in the form of a shell. Whenthe casing is closed, the current telephone call is disconnected and thecellular phone enters a low power consumption mode.

More specifically, with reference to FIG. 19, the cellular phone ispowered off (step S1). Whether or not the power supply key has beenpressed, is detected (step S2). If so then a liquid crystal display, abacklight and the like are turned on (step S3). If not then the controlreturns to step S1.

Then a standby status is conferred (step S4) and the control determineswhether a call key has been pressed (step S5). If so then a call statusis conferred (step S6). If not then the control moves on to step S10 todetermine whether the casing in the form of the shell is open or closed.

During a call, the control determines whether a disconnection key hasbeen pressed to disconnect the call (step S7). If so then the controlreturns to step S4.

If not then the control determines whether the casing has been closed(step S8). If not then the control returns to step S6.

If so the call is disconnected (step S9) and the cellular phone isconferred a standby status on with the casing closed (step S11). In thestep S11 condition a low power supply consumption mode is set.

At step S10 if the control determines that the casing has been closedthen the control moves on to step S11 and if the control determines thatthe casing is open then the control moves on to step S4.

In the step S11 condition, the control determines whether the casing isopen or closed (step S12) and if the casing is closed then the controlstays at step S11 and if the casing is opened then the control moves onto step S3.

In other words, to continue a call (including mails, communications viapersonal computers, and the like) the conventional cellular phone in theform of a shell must have its casing in the form of the shell kept open.

Conventional cellular phones in the form of a shell cannot download orreproduce encrypted content data with a copyright sufficientlyprotected, a license key and the like. If the encrypted content data,the license key and the like are configured to be downloaded andreproducible, the cellular phone still needs to have its casing in theform of the shell kept open while it downloads or reproduces the data,the key and the like. Such is particularly inconvenient if a largeamount of data such as music content is downloaded and reproduced as thecasing needs to be kept open for a long period of time.

SUMMARY OF THE INVENTION

Therefore the present invention contemplates a data terminal devicehaving a casing in the form of a shell and capable of continuing todownload encrypted content data, a license key and the like or reproduceencrypted content data with the casing closed.

The present invention in one aspect provides a data terminal deviceaccommodated in a casing in a form of a shell, downloading from adistribution server encrypted content data and a license key decryptingthe encrypted content data, and reproducing the encrypted content data,including: a communication unit externally effecting a communication; adata recording device recording the encrypted content data and thelicense key therein, and receiving authentication data and outputtingthe license key only when the authentication data is authenticated; aninterface; a control unit; a detection unit detecting whether the casingis open/closed; and a power supply control unit controlling whether tosupply various components with power.

When the detection unit detects that the casing is closed download ofthe encrypted content data is started, the power supply control unitcontrols supplying power required for a call to complete downloading theencrypted content data. Preferably, when the data terminal device withthe casing closed completes downloading the encrypted content data, thepower supply control unit for example stops supplying the power andcontrols a standby mode function of the various components internal tothe data terminal device to shift the data terminal device to a lowpower consumption mode.

Or the data terminal device includes a reproduction unit and when thedetection unit detects that the casing is closed after reproduction ofthe encrypted content data is started the power supply control unitcontrols supplying power required for a reproduction process to completereproducing the encrypted content data. Preferably, when the dataterminal device with the casing closed completes reproducing theencrypted content data, the power supply control unit for example stopssupplying the power and controls a standby mode function of the variouscomponents internal to the data terminal device to shift the dataterminal device to a low power consumption mode.

The present invention in another aspect provides a data terminal deviceaccommodated in a casing in a form of a shell, downloading from adistribution server encrypted content data and a license key decryptingthe encrypted content data, recording the encrypted content data and thelicense key in a data recording device, and reproducing the encryptedcontent data via the data recording device, including: a communicationunit; an interface; a control unit; a detection unit; and a power supplycontrol unit.

When the detection unit detects that the casing is closed after downloadof the encrypted content data is started, the power supply control unitcontrols supplying power required for a call to complete downloading theencrypted content data. Preferably, when the data terminal device withthe casing closed completes downloading the encrypted content data, thepower supply control unit for example stops supplying the power andcontrols a standby mode function of the various components internal tothe data terminal device to shift the data terminal device to a lowpower consumption mode.

Or the data terminal device includes a reproduction unit and when thedetection unit detects that the casing is closed after reproduction ofthe encrypted content data is started the power supply control unitcontrols supplying power required for a reproduction process to completereproducing the encrypted content data. Preferably, when the dataterminal device with the casing closed completes reproducing theencrypted content data, the power supply control unit for example stopssupplying the power and controls a standby mode function of the variouscomponents internal to the data terminal device to shift the dataterminal device to a low power consumption mode.

Thus if the present device has its casing closed while it is downloadingencrypted content data, it still can complete downloading the data. Inparticular, it is no longer necessary to leave the device with thecasing open if it downloads a large amount of data such as musiccontent.

Furthermore if the present device has its casing closed while it isreproducing encrypted content data, it still can complete reproducingthe data. This eliminates the necessity of leaving the device with thecasing open.

Furthermore the present device can download and reproduce encryptedcontent data while the copyright of the data can sufficiently beprotected.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing:

FIG. 1 is a schematic diagram illustrating a concept of a datadistribution system;

FIGS. 2A, 2B and 2C show a cellular phone with its casing in the form ofa shell opened and closed;

FIGS. 3–5 are tables of data, information and the like used in the FIG.1 data distribution system for communication;

FIG. 6 is a schematic block diagram showing a configuration of a licenseserver;

FIG. 7 is a block diagram showing a configuration of a cellular phone;

FIG. 8 is a block diagram showing a configuration of a memory card;

FIGS. 9 and 10 are first and second flow charts, respectively, forillustrating a distribution operation in the FIG. 1 data distributionsystem;

FIGS. 11 and 12 are first and second flow charts, respectively, forillustrating a reproduction operation in a cellular phone;

FIG. 13 is a flow chart representing a relationship between opened andclosed positions of a casing of a cellular phone in the form of a shellin the first embodiment and a download process;

FIG. 14 is a flow chart representing a relationship between the openedand closed positions of the casing of cellular phone in the form of theshell in the first embodiment and a reproduction process;

FIG. 15 is a block diagram showing a configuration of a main body of acellular phone in a second embodiment;

FIG. 16 is a block diagram showing a configuration of a musicreproduction module in the second embodiment;

FIG. 17 is a schematic diagram for illustrating a concept ofdistributing encrypted content data by means of a computer;

FIG. 18 is another schematic diagram for illustrating a concept ofdistributing encrypted content data by means of a computer; and

FIG. 19 is a flow chart for illustrating a power supply to aconventional cellular phone in the form of a shell.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention will now be described withreference to the drawings more specifically. In the figures, likeportions are denoted by like reference characters.

First Embodiment

FIG. 1 is a schematic diagram for illustrating a concept of a generalconfiguration of a data distribution system wherein a distributionserver distributes encrypted content data, which a data terminal deviceof present invention reproduces, to a memory card.

Note that hereinafter a description will by way of example be providedof a configuration of a data distribution system distributing digitalmusic data to each cellular phone user on a cellular phone network,although, as will be apparent from the following description, thepresent invention is not limited thereto and it is also applicable todistributing content data corresponding to other types of creations,such as image data, animated image data, and the like. Furthermore thepresent invention is also applicable to distribution on differentinformation communication networks.

With reference to FIG. 1, license server 10, managing copyrighted musicdata, is accessed by a cellular phone user 1 requesting a datadistribution via a cellular phone 100 having a memory card 110 attachedthereto. The server effects an authentication process to determinewhether memory card 110 holds proper authentication data or memory card110 is a proper memory card and if so then it uses a predeterminedencryption system to encrypt music data (hereinafter also be referred toas content data) and provides such encrypted content data to a cellularphone company corresponding to a distribution carrier 20 distributingdata.

Distribution carrier 20 receives a distribution request from eachcellular phone user and relays it via its cellular phone network tolicense server 10. License server 10, in response to the distributionrequest, confirms whether the memory card or the like is properequipment and if so then license server 10 encrypts the requestedcontent data and distributes the encrypted content data on the cellularphone network of distribution carrier 20. The data is thus distributedto the cellular phone of the cellular phone user and thus received bythe memory card attached thereto.

In FIG. 1, for example a cellular phone user 1 uses a cellular phone 100with a detachable memory card 110 attached thereto. Memory card 110receives the encrypted content data received by cellular phone 10 andstores the data. Furthermore, memory card 110 receives a license keythrough an authentication process effected for the aforementioneddistribution and stores data. Then memory card 110 decrypts encrypteddata and provides the decrypted data to a music reproduction unit (notshown) of cellular phone 100.

Furthermore, a cellular phone user can listen, for example via aheadphone 130 connected to cellular phone 100, to encrypted content datathat is decrypted with a license key and thus “reproduced.”

Hereinafter, such license server 10 and distribution carrier 20 willgenerally be referred to as a distribution server 30.

Furthermore, a process of transmitting content data from distributionserver 30 for example to each cellular phone will be referred to as“distribution.”

Cellular phone 100 has a casing in the form of a shell, as shown inFIGS. 2A–2C. The casing is formed of a main body 3000, a flap 3002 and amovable joint 3004. For example, main body 3000 has keys 1108 arrangedto allow a user to input data, and flap 3002 has a display 1100 arrangedto display data. Movable joint 3004 allows cellular phone 100 to beclosed from an opened position as shown in FIGS. 2A and 2B to a closedposition as shown in FIG. 2C and also opened from the FIG. 2C closedposition to the FIGS. 2A and 2B opened position.

As will be described hereinafter, a detection unit 1117 detects whetherthe casing in the form of the shell is open or closed. For example, itdetermines that the casing is closed when a specific portion 3008 a on asurface of main body 3000 is brought into contact with a specificportion 3008 b on a surface of flap 3002.

As has been described above, when it has been confirmed that memory card110 attached to cellular phone 100 is a proper memory card, distributionserver 30 distributes content data. As such, first of all, if memorycard 110 is not used, content data distributed by distribution server 30can hardly be received or reproduced as music.

Furthermore, if whenever distribution carrier 20 distributes the contentdata of a single piece of music the distribution frequency incrementsand whenever a cellular phone user receives or downloads the contentdata a copyright fee incurs and it is collected by distribution carrier20 together with the phone toll of the cellular phone, the copyrightowner can readily collect the copyright fee.

In such a configuration, to allow encrypted and distributed content datato be reproduced on the side of a cellular phone user, a system isinitially required to be a system for distributing an encryption key ina communication, secondly the exact system encrypting content data to bedistributed, thirdly a configuration implementing content dataprotection for preventing such distributed content data from beingcopied without permission, and fourthly a configuration capable ofcompleting a currently continuing process (e.g., a download process, areproduction process) with the casing in the form of a shell closed.

In the first embodiment, in particular when any of distribution andreproduction sessions occurs, whether or not the content data'sdestination is a proper destination can be determined and checkedseverely, and for any recording devices and content reproduction devices(cellular phones) that are not authenticated or are with a decryptionkey broken, outputting the content data thereto can be prevented and thecopyright of the content data can thus more firmly be protected, andfurthermore in a cellular phone with the casing in the form of a shellclosed a currently continuing download process or reproduction processstill can be completed.

FIG. 3 is a list of characteristics of data, information and the likeused in the FIG. 1 data distribution system for a communication.

Initially, data distributed from distribution server 30 will bedescribed. “Data” is content data such as music data. Content data Datais encrypted, decryptable with a license key Kc. It is encrypted withlicense key (hereinafter also be referred to as a “content key”) Kc tobe decryptably encrypted content data {Data} Kc which is in turndistributed from distribution server 30 to a cellular phone user.

Note that hereinafter, a representation {Y} X will refer to data Yencrypted decryptable with a decryption key X.

Furthermore, distribution server 30 distributes together with theencrypted content data additional information Data-inf corresponding toplaintext information on the copyright of content data, server access,and the like. Furthermore, as the license information, there exist acontent ID serving as a code for identifying content data Data and alicense ID serving as a management code capable of specifying anissuance of a license, and access restriction information AC1 andreproduction circuit control information AC2 generated from licensepurchasing condition AC including a number of licenses, a limitation ona function and other similar information that are determined asdesignated by a user. Hereinafter license key Kc, the content ID, thelicense ID, access control information AC1 and reproduction circuitcontrol information AC2 will generally be referred to as a license.

Reference will now be made to FIG. 4 to describe characteristics ofdata, information and the like used in the FIG. 1 data distributionsystem for an authentication and operating a revocation class list.

In the first embodiment a class revocation list (CRL) is used to revokecontent data distribution and reproduction for each recording device(memory card) class and each content data reproducing, data terminaldevice (cellular phone) class. Hereinafter, CRL will also represent datain the class revocation list, as required.

Information related to the class revocation list includes classrevocation list data CRL listing classes of data terminal devices andmemory cards that are revoked from license distribution andreproduction.

Class revocation list data CRL is managed in distribution server 30 andalso recorded and thus held in a memory card. Such a class revocationlist needs to be upgraded, as appropriate, to update data. To change thedata, distribution server 30 generates differential data CRL_datbasically reflecting only the changed portion(s) of the data and classrevocation list CRL in the memory card is rewritten accordingly.Furthermore, the version of the class revocation list is managed bydistribution server 30, which receives and confirms CRL_ver output fromthe memory card. Differential data CRL_dat also includes information ona new version. Furthermore the version information may includes a dateand time when the data is updated.

Thus class revocation list CRL can be held and managed not only in adistribution server but also in a memory card to revoke distributing alicense key to a data terminal device and memory card with a decryptionkey unique to the class, or a decryption key unique to the type of thedata terminal device and memory card, broken. Thus the data terminaldevice cannot reproduce content data and the memory card cannot transfercontent data.

Thus, class revocation list CRL in a memory card is configured to havedata updated successively when distribution is effected. Furthermore ina memory card class revocation list CRL is managed for example byrecording it in a memory card at a tamper resistant module independentlyof the upper level(s) to prevent class revocation list data CRL frombeing improperly changed from the upper level(s) by means for example offile systems, application programs and the like. Thus, protection ofcopyright of data can further be enhanced.

A data terminal device (a cellular phone) and a memory card are providedwith unique public encryption keys KPpn and KPmci, respectively. Publicencryption keys KPpn and KPmci are decryptable with a secret decryptionkey Kpn unique to the data terminal device and a secret decryption keyKmci unique to the memory card, respectively. These public encryptionand secret decryption keys each have a different value for each dataterminal device type and each memory card type. These public encryptionand secret decryption keys will generally be referred to as a class key.

Furthermore, there are also provided class certificates Crtfn and Cmcifor a reproduction circuit and a memory card, respectively.

These class certificates have different information for each memory cardclass and each content reproduction unit (cellular phone) class. A classkey with an encryption thereby broken, i.e., that with a secretdecryption key obtained is listed on the class revocation list and thusprevented from license issuance.

The public encryption keys and class certificates unique to the memorycard and the content reproduction unit are recorded in a memory card anda cellular phone in the form of authentication data {KPmci//Cmci}KPmaand {KPpn//Crtfn}KPma, respectively, when they are shipped. As will bedescribed more specifically, KPma represents a public authentication keyshared throughout a distribution system.

FIG. 5 collectively describes characteristics of keys relating to anencryption process in the FIG. 1 data distribution system.

When a memory card externally communicates data, encryption keys Ks1–Ks3are used to keep the secret. Keys Ks1–Ks3 are common keys generated byserver 30, cellular phone 100, and memory card 110 whenever content datais distributed and reproduced.

Herein, common keys Ks1–Ks3 are unique common keys generated for each“session” corresponding to a unit of communication or a unit of accessbetween a server, a cellular phones and a memory cards and hereinafterwill also be referred to as “session keys.”

Session keys Ks1—Ks3 each have a unique value for each communicationsession and thus managed by a distribution server, a cellular phone anda memory card. More specifically, session key Ks1 is generated by thedistribution server for each distribution session. Session key Ks2 isgenerated by the memory card for each distribution session and eachreproduction session, and session key Ks3 is generated in the cellularphone for each reproduction session. In each session, these session keyscan be communicated at a session key generated by other equipment can bereceived and used to effect encryption and a license key and the likecan then be transmitted to enhance security in the session.

Furthermore, as a key for managing a data-processing in memory card 110,there exist a public encryption key KPm set for each mediumcorresponding to a memory card and a secret decryption key Km unique toeach memory card and capable of decrypting data encrypted with publicencryption key KPm.

FIG. 6 is a schematic block diagram showing a configuration of the FIG.1 license server 10.

License server 10 includes an information database 304 provided to holdcontent data encrypted in a predetermined system, information ondistribution for example of a license ID and the like, an accountdatabase 302 provided to hold account information for each cellularphone user starting an access to content data, a CRL database 306provided to manage class revocation list CRL, a data processing unit 310receiving data from information database 304, account database 302 andCRL database 306 via a data bus Bs1 and processing the received data, aspredetermined, and a communication device 350 communicating data betweendistribution carrier 20 and data processing unit 310 on a communicationnetwork.

Data processing unit 310 includes a distribution control unit 315receiving data on data bus BS1 and accordingly controlling an operationof data processing unit 310, a session key generation unit 316controlled by distribution control unit 315 to generate session key Ks1in a distribution session, a decryption unit 312 receiving viacommunication device 350 and on data bus BS1 authentication data{KPmci//Cmci}KPma for authentication transmitted from a memory card anda cellular phone, and decrypting the received data with publicauthentication key KPma, an encryption unit 318 encrypting session keyKs1 generated by session key generation unit 316, with public encryptionkey KPmci obtained by decryption unit 312, for output on data bus BS1,and a decryption unit 320 receiving and decrypting data encrypted withsession key Ks1 and then transmitted on data bus BS1.

Data processing unit 310 further includes an encryption unit 326encrypting license key Kc and reproduction circuit control informationAC2 received from distribution control unit 315 with public encryptionkey KPm obtained by decryption unit 320 that is unique to a memory card,and an encryption unit 328 further encrypting an output of encryptionunit 326 with session key Ks2 received from decryption unit 320, foroutput on data bus BS1.

License server 10 in a distribution session operates, as will later bedescribed with reference to a flow chart.

FIG. 7 is a schematic block diagram for illustrating a configuration ofthe FIG. 1 cellular phone 100.

Cellular phone 100 includes an antenna 1102 receiving a signaltransmitted on a cellular phone network by wireless, a transmission andreception unit 1104 receiving a signal from antenna 1102 and convertingthe received signal to a baseband signal or modulating data receivedfrom the cellular phone and providing the modulated data to antenna1102, a data bus BS2 allowing data communication between components ofcellular phone 100, and a controller 1106 controlling an operation ofcellular phone 100 via data bus BS2.

Cellular phone 100 further includes a key operation unit 1108 operatedto input an external instruction to cellular phone 100, a display 1100presenting information output for example from controller 1106 to acellular phone user visibly, and an audio reproduction unit 1112operative in a normal conversation operation to reproduce speech basedon data received on data bus BS2.

Cellular phone 100 also includes a DA converter 1113 converting anoutput of audio reproduction unit 1112 from a digital signal to ananalog signal, and a terminal 1114 outputting an output of DA converter1113 for example to an external output device.

Cellular phone 100 further includes a detachably attachable memory card110 storing and decrypting content data (music data) received fromdistribution server 30, and a memory interface 1200 controlling datacommunication between memory card 110 and data bus BS2.

Cellular phone 100 further includes an authentication data hold unit1202 holding authentication data {KPp1//Crtf1}KPma, an encryption ofpublic encryption key KPp1 and class certificate Crtf1 set for eachcellular phone type (or class) that has its authenticity verified whenthey are decrypted with public decryption key KPma.

Cellular phone 100 further includes a Kp1 hold unit 1204 holding adecryption key Kp1 unique to the class of the cellular phone (thecontent reproduction circuit), and a decryption unit 1206 usingdecryption key Kp1 to decrypt data received on data bus BS2, andobtaining session key Ks2 generated by memory card 110.

Cellular phone 100 further includes a session key generation unit 1210using a random number or the like to generate session key Ks3 forencrypting data communicated with memory card 110 on data bus BS2 in areproduction session reproducing content data stored in memory card 110,and an encryption unit 1208 using session key Ks2 obtained by decryptionunit 1206, to encrypt generated session key Ks3 for output on data busBS2.

Cellular phone 100 further includes a decryption unit 1212 using sessionkey Ks3 to decrypt data on data bus BS2 for output.

Cellular phone 100 further includes a decryption unit 1214 receivingencrypted content data {Data}Kc on data bus BS2, decrypting the receiveddata with license key Kc obtained from decryption unit 1212, andoutputting content data, a music reproduction unit 1216 receiving anoutput of decryption unit 1214 and reproducing content data, a DAconverter 1218 converting an output of music reproduction unit 1216 froma digital signal to an analog signal, a switch 1222 receiving outputs ofDA converters 1113 and 1218 for selective output depending on the modeof operation through terminal 1114 or 1220, and a connection terminal1224 receiving and connecting an output of switch unit 1222 to aheadphone 130.

Cellular phone 100 also includes a power supply control unit 1116controlled by controller 1106 to control whether or not to supply powerapplied to operate each circuit in cellular phone 100, and a detectionunit 1117 detecting whether cellular phone 100 has its casing in theform of the shell in a closed position or an opened position. Detectionunit 1117 outputs a result of detection which is in turn transferred ondata bus BS2 to controller 1106.

As will be described hereinafter, controller 1106 is driven by theresult received from detection unit 1117, to control a power supplycontrol block 1116 effecting a power supply process, a data downloadprocess, a data reproduction process, and the like.

Note that for the purpose of simplifying the description, FIG. 7 onlyshows a cellular phone at a block relating to distribution andreproduction of music data in accordance with the present invention. Thecellular phone of course has a block relating to conversation, which isonly partially described herein.

In cellular phone 100 each component operates in each session, as willlater be described more specifically with reference to a flow chart.

FIG. 8 is a schematic block diagram for illustrating a configuration ofmemory card 110. As has been described previously, there are providedpublic encryption key and secret decryption key KPmci and Kmci unique toeach memory card and a memory card class certificate Cmci and for memorycard 110 natural number i=1 for the sake of convenience.

Thus memory card 110 includes an authentication data hold unit 1400holding authentication data {KPmc1//Cmc1}KPma, a Kmc hold unit 1402holding a unique decryption key Kmc1 set for each memory card type, aKm1 hold unit 1421 holding secret decryption key Km1 set unique to eachmemory card, and a KPm1 hold unit 1416 holding public encryption keyKPm1 decryptable with Km1. Authentication data hold unit 1400 holdspublic encryption key KPmc1 and class certificate Cmc1 set for eachmemory card type and class, in the form of authentication data{KPmc1//Cmc1}KPma, an encryption of the key and the certificate that hasits authenticity verified when it is decrypted with publicauthentication key KPma.

By thus providing an encryption key of a recording device correspondingto a memory card, distributed content data, an encrypted license key andthe like can be managed for each memory card.

Memory card 110 further includes a data bus BS3 communicating a signalwith memory interface 1200 via a terminal 1201, a decryption unit 1404receiving data on data bus BS3 via memory interface 1200 and secretdecryption key Kmc1 unique to each memory card type from Kmc1 hold unit1402, and outputting to a contact Pa session key Ks1 generated bydistribution server 30 in a distribution session, a decryption unit 1408receiving public authentication key KPma from KPma hold unit 1414, usingpublic authentication key KPma to decrypt data received on data bus BS3,and outputting a result of the decryption to encryption unit 1410, andan encryption unit 1406 using a key selectively provided via switch1442, to encrypt data selectively provided via switch 1444, for outputon data bus BS3.

Memory card 110 further includes a session key generation unit 1418generating session key Ks2 in each of distribution and reproductionsessions, a encryption unit 1410 encrypting session key Ks2 output fromsession key generation unit 1418, with public encryption key KPpn orKPmci obtained by decryption unit 1408, for output on data bus BS3, anda decryption unit 1412 receiving on BS3 the data encrypted with sessionkey Ks2, decrypting the received data with session key Ks2 obtained fromsession key generation unit 1418, and outputting a result of thedecryption on data bus BS4.

Memory card 110 further includes a decryption unit 1422 decrypting dataon data bus BS4 with secret decryption key Km1 unique to memory card 110and paired with public encryption key KPm1, and a memory 1415 receivingon data bus BS3 and storing therein license key Kc, reproduction circuitcontrol information AC2 and reproduction information (a content ID, alicense ID, access control information AC1) encrypted with publicencryption key KPm1 and class revocation list data CRL updated, asappropriate, by differential data CRL_dat provided to update a versionof the class revocation list that is not encrypted, and also receivingand storing therein encrypted content data {Data}Kc and additionalinformation Data-inf transmitted on data bus BS3. Memory 1415 is forexample a semiconductor memory device.

Memory card 110 further includes a license information hold unit 1440holding a license ID, a content ID and access restriction informationAC1 obtained by decryption unit 1422, and a controller 1420communicating data externally on data bus BS3 and receiving reproductioninformation and the like on data bus BS4 to control an operation ofmemory card 110.

License information hold unit 1440 is capable of transmitting andreceiving the data of a content ID, a license ID, access controlinformation AC1 on data bus BS4. License information hold unit 1440 hasN banks, wherein N represents a natural number, and holds for each bankthe license information corresponding to each license.

Note that in FIG. 8, the portion surrounded by a solid line is adaptedto be incorporated in memory card 110 at a module TRM so that forexample when it is externally, improperly opened, internal data iserased or internal circuitry is destroyed to prevent a third party fromreading for example data in a circuit existing in the portionsurrounding by the solid line. Such a module is typically the tamperresistant module.

Of course memory 1415 may also together be incorporated into module TRM,although in the FIG. 8 configuration, with memory 1415 holdingreproduction information required for reproduction, all in the form ofencrypted data, a third party simply having the data in memory 1415cannot reproduce music and furthermore it is not necessary to arrangememory 1415 in the expensive tamper resistance module and the productioncost can thus be reduced.

The FIG. 1 data distribution system operates in each session, as willnow be described more specifically with reference to a flow chart.

FIGS. 9 and 10 are first and second flow charts, respectively, forillustrating a distribution operation (hereinafter also referred to as adistribution session) provided in purchasing content in the FIG. 1 datadistribution system.

In FIGS. 9 and 10 is described an operation when cellular phone user 1uses memory card 110 to receive via cellular phone 100 content datacorresponding to music data distributed from distribution server 30.

Initially, cellular phone user 1 of cellular phone 100 for examplepresses a key button on key operation unit 1108 to issue an request todistribute data (step S100).

In memory card 110 responds to the distribution request by allowingauthentication data hold unit 1400 to output authentication data{KPmc1//Cmc1}KPma (step S102).

Cellular phone 100 transmits authentication data {KPmc1//Cmc1}KPmareceived from memory card 110 for authentication, as well as a contentID and license purchasing condition data AC to distribution server 30(step S104).

Distribution server 30 receives the content ID, authentication data{KPmc1//Cmc1}KPma and license purchasing condition data AC from cellularphone 100 (step S106) and decryption unit 312 effects a decryptionprocess using public authentication key KPma to decrypt theauthentication data output from memory card 110 (step S108).

Distribution control unit 315 is driven by a result of the decryptionprocess in decryption unit 312 to effect an authentication process todetermine whether the process of interest has been normally effected,i.e., to authenticate that memory card 110 holds public encryption keyKPmc1 and certificate Cmc1 of a proper memory card. In doing so,distribution control unit 315 in the authentication process determineswhether authentication data encrypted by an authorizer to verify itsauthenticity is received (step S110). If so then distribution controlunit 315 approves and accepts public encryption key KPmc1 andcertificate Cmc1 and moves on to a subsequent step (step S112). If notthen the control does not approve or accept public encryption key KPmc1or certificate Cmc1 and terminates the process (step S170).

When the authentication process reveals that the equipment of interestis proper equipment, distribution control unit 315 sends to CRL database306 a query as to whether memory card 110 has class certificate Cmc1listed on class revocation list CRL. If so then the distribution sessionends (step S170).

If not then the control moves on to a subsequent step (step S112).

If the authentication process reveals that a cellular phone having amemory card with proper authentication data is demanding an access andthat the class is not found on the class revocation list then indistribution server 30 session key generation unit 316 produces sessionkey Ks1 for distribution. Session key Ks1 is encrypted by encryptionunit 318 using public encryption key KPmc1 obtained by decryption unit312 and corresponding to memory card 110 (step S114).

Encrypted session key Ks1 is externally output as {Ks1}Kmc1 on data busBS1 and via communication device 350 (step S116).

When cellular phone 100 receives encrypted session key {Ks1}Kmc1 (stepS118), in memory card 110 the received data received via memoryinterface 1200 and transmitted on data bus BS3 is decrypted bydecryption unit 1404 using secret decryption key Kmc1 held in Kmc1 holdunit 1402 and unique to memory card 110 and session key Ks1 is thusdecrypted and extracted (step S120).

When controller 1420 confirms that session key Ks1 generated bydistribution server 30 has accepted, it instructs session key generationunit 1418 to generate session key Ks2, which memory card 110 generatesin a distribution session.

Furthermore, in the distribution session, controller 1420 extractsversion data CRL_ver of the class revocation list stored in memory 1415and outputs the data on data bus BS4. Data CRL_ver is information on acondition (a version) of the class revocation list recorded in memorycard 110 at memory 1415.

Encryption unit 1406 uses session key Ks1 received from decryption unit1404 via a contact Pa of switch 1442, to encrypt session key Ks2, publicencryption key KPm1 and class revocation list version data CRL_verprovided via switches 1444 and 1446 having their respective contactsswitched successively and provide them in a series of data and outputencrypted data {Ks2//KPm1//CRL_ver}Ks1 on data bus BS3 (step S122).

Encrypted data {Ks2//KPm1//CRL_ver}Ks1 output on data bus BS3 is outputtherefrom via terminal 1201 and memory interface 1200 to cellular phone100 and transmitted from cellular phone 100 to distribution server 30(step S124).

Distribution server 30 receives encrypted data {Ks2//KPm1//CRL_ver}Ks1,in decryption unit 320 decrypts the data with session key Ks1, andaccepts session key Ks2 generated in memory card 110, public encryptionkey KPm1 unique to memory card 110, and class revocation list versiondata CRL_ver in memory card 110 (step S126).

Class revocation list version information CRL_ver is transmitted on databus BS1 to distribution control unit 315, which generates differentialdata CRL_dat according to the accepted version data CRL_ver (step S128). Differential data CRL_dat represents a variation between theversion of the CRL_ver of interest and the current version of the classrevocation list data in CRL database 306.

Furthermore, distribution control unit 315 generates a license ID,access restriction information AC1 and reproduction circuit controlinformation AC2 according to content ID and license purchasing conditionAC obtained at step S106 (step S130). Furthermore it obtains license keyKc from information database 304 to decrypt encrypted content data (stepS132).

With reference to FIG. 10, distribution control unit 315 provides agenerated license, i.e., license key Kc, reproduction circuit controlinformation AC2, a license ID, a content ID and access restrictioninformation AC1 to encryption unit 326, which in turn encrypts thelicense with public encryption key KPm1 obtained by decryption unit 320and unique to memory card 110 (step S136). Encryption unit 328 receivesan output of encryption unit 326 and differential data CRL_dat of theclass revocation list output from distribution control unit 315 on databus BS1 and encrypts them with session key Ks2 generated in memory card110. Encryption unit 328 outputs the encrypted data which is in turntransmitted on data bus BS1 and via communication device 350 to cellularphone 100 (step S138).

Thus, a distribution server and a memory card generate encryption keys,respectively, mutually communicate the encryption keys, use them toeffect encryption, and mutually transmit the encrypted data. Thus intransmitting and receiving their respective encrypted data a mutualauthentication can in effect also be achieved to enhance the security ofthe data distribution system.

Cellular phone 100 receives encrypted data {{Kc//AC2//licenseID//content ID//AC1 }Km1//CRL_dat}Ks2 transmitted (step S140) andoutputs it to memory card 110 via memory interface 1200. In memory card110 decryption unit 1412 decrypts the data transmitted via memoryinterface 1200 and on data bus BS3. Decryption unit 1412 uses sessionkey Ks2 received from session key generation unit 1418 to decrypt thereceived data on data bus BS3 for output on data bus BS4 (step S142).

Output at this stage on data bus BS4 are encrypted license{KC//AC2//license ID//content ID//AC1}Km1 decryptable with secretdecryption key Km1 held in Km1 hold unit 1421, and CRL_dat. According toan instruction from controller 1420, encrypted license {KC//AC2//licenseID//content ID//AC1}Km1 is recorded in memory 1415 (step S144). On theother hand, encrypted license {KC//AC2//license ID//content ID//AC1}Km1is decrypted by decryption unit 1422 using secret decryption key Km1,and of the license, only the license ID, the content ID and accessrestriction information AC1, which are referenced in memory card 110,are accepted (step S 146).

Controller 1420 is driven by the received CRL_dat to update classrevocation list data CRL in memory 1415 and the version thereof (stepS148). The license ID, the content ID and access restriction informationAC1 are recorded in license information hold unit 1440 (step S150).

When the process up to step S150 normally completes in a memory card,cellular phone 100 sends a request to distribution server 30 todistribute content data (step S152).

Distribution server 30 receives the content data distribution request,obtains encrypted content data {Data}Kc and additional informationData-inf from information database 304 and outputs these data on databus BS1 and via communication device 350 (step S154).

Cellular phone 100 receives {Data}Kc//Data-inf and accepts encryptedcontent data {Data}Kc and additional information Data-inf (step S156).Encrypted content data {Data}Kc and additional information Data-inf aretransmitted via memory interface 1200 and terminal 1201 to data bus BS3of memory card 110. Memory card 110 records the received encryptedcontent data {Data}Kc and additional information Data-inf in memory 1415as they are (step S158).

Furthermore, memory card 110 transmits to distribution server 30 anotification that the distribution has been accepted (step S160) andwhen distribution server 30 receives the notification (step S162) aprocess to complete the distribution is carried out including e.g.,storing account data to account database 302 (step S164) and the entireprocess ends (step S170).

Thus memory card 110 attached to cellular phone 110 is confirmed asproper equipment and public encryption keys KPp1 and KPmc1 successfullyencrypted and transmitted together with class certificate Cmc1 are alsoconfirmed valid, and only then can content data be distributed inresponse only to a distribution request from a memory card without classcertificate Cmc1 found in the class revocation list, i.e., a classcertificate list with encryption by means of public encryption keys KPp1and KPmc1 that is broken. Thus, distribution to an improper memory cardand distribution using a deciphered class key can be prevented.

Reference will now be made to FIGS. 11 and 12 to describe a reproductionoperation of cellular phone 100 reproducing content data distributed tomemory card 110. With reference to FIG. 11, when the reproductionoperation starts, user 1 of cellular phone 100 operates a key operationunit 1108 to input an instruction to cellular phone 100 to reproducecontent data (step S200). Then controller 1106 reads authentication data{KPp1//Crtf1}KPma from authentication data hold unit 1202 via data busBS2 and input authentication data {KPp1//Crtf1}KPma to memory card 110via memory interface 1200 (step S201).

Then memory card 110 accepts authentication data {KPp1//Crtf1}KPma (stepS202). Then in memory card 110 decryption unit 1408 decrypts theaccepted authentication data {KPp//Crtf1}KPma with public authenticationkey KPma held in KPma hold unit 1414 (step S203) and controller 1420effects an authentication process from a result of a decryption processeffected by decryption unit 1408. More specifically, controller 1420effects an authentication process to determine whether authenticationdata {KPp1//Crtf1}KPma is proper authentication data (step S204). If thedata cannot be decrypted, controller 1420 provides an output indicativeof non-acceptance of the authentication data via data bus BS3 andterminal 1201 to memory interface 1200 of cellular phone 100 (stepS206). If the authentication data can be decrypted, controller 1420determines whether the obtained certificate Crtf1 is included in theclass revocation list data read from memory 1415 (step S205). Sincecertificate Crtf1 has been provided with an ID and controller 1420 thusdetermines whether the received certificate Crtf1 has an ID existing inthe class revocation list data. If controller 1420 determines thatcertificate Crtf1 is included in the class revocation list data thencontroller 1420 provides an output indicative of non-acceptance of theauthentication data via data bus BS3 and terminal 1201 to memoryinterface 1200 of cellular phone 100 (step S206).

If at step S204 authentication data cannot be decrypted with publicauthentication key KPma and certificate Crtf1 accepted at step S205 isincluded in the class revocation list data, an output is providedindicating that the authentication data is not accepted. In cellularphone 100 when controller 1106 receives via memory interface 1200 theoutput indicating that the authentication data is not accepted, itdisplays on display 1100 that the data of interest cannot be reproducedowing to the non-acceptance of the authentication data (step S207).

If at step S205 the control determines that certificate Crtf1 is notincluded in the class revocation list data then, with reference to FIG.12, in memory card 110 a session key generation unit 1418 generates asession key Ks2 for a reproduction session (step S208). Then encryptionunit 1410 outputs on data bus BS3 the session key Ks2 output fromsession key generation unit 1418 that is encrypted with publicencryption key KPp1 decrypted by decryption unit 1418, i.e., encrypteddata {Ks2}Kp1 (step S209). Then controller 1420 outputs encrypted data{Ks2}Kp1 to memory interface 1200 via terminal 1201 and controller 1106in cellular phone 100 obtains encrypted data {Ks2}Kp1 via memoryinterface 1200. Then Kp1 hold unit 1204 outputs secret decryption keyKp1 to decryption unit 1206.

Decryption unit 1206 decrypts encrypted data {Ks2}Kp1 with secretdecryption key Kp1 output from Kp1 hold unit 1204 that is paired withpublic encryption key KPp1, and decryption unit 1206 outputs session keyKs2 to encryption unit 1208 (step S210). Then session key generationunit 1210 generates session key Ks3 for a reproduction session andoutputs session key Ks3 to encryption unit 1208 (step S211). Encryptionunit 1208 receives session key Ks3 from session key generation unit 1210and encrypts it with session key Ks2 received from decryption unit 1206and thus outputs encrypted data {Ks3}Ks2 and controller 1106 outputsencrypted data {Ks3}Ks2 on data bus BS2 and via memory interface 1200 tomemory card 110 (step S212).

In memory card 110 decryption unit 1412 receives encrypted data {Ks3}Ks2via terminal 1201 and data bus BS3 and decrypts encrypted data {Ks3}Ks2with session key Ks2 generated by session key generation unit 1418 andthus obtains session key Ks3 generated in cellular phone 100 (stepS213).

In response to the acceptance of session key Ks3, controller 1420confirms the corresponding access restriction information AC1 existingin license information hold unit 1440 (step S214).

At step S214 is confirmed access restriction information AC1, theinformation on a restriction imposed on memory access. If it indicatesthat reproduction is disallowed then the control terminates thereproduction operation. If it indicates that reproduction is allowedonly as many times as limited then the control updates data of accessrestriction information AC1 to update the frequency of reproductionallowed and then moves on to a subsequent step (step S215). If accessrestriction information AC1 does not limit a reproduction frequency thenthe control skips step S215 and without updating reproduction controlinformation AC1 moves on to a subsequent step (step S216).

If license information hold unit 1440 does not hold the content ID of asong requested, the control also determines that reproduction isdisallowed and the control terminates the reproduction session.

If at step S214 the control determines that reproduction is possible inthe reproduction operation of interest, then a decryption process iseffected to decrypt a license including license key Kc recorded inmemory 1415 and associated with a song requested to be reproduced. Morespecifically, in response to an instruction from controller 1420,encrypted license {Kc//AC2//license ID//content ID//AC1}Km1 read frommemory 1415 onto data bus BS4 is decrypted by decryption unit 1422 usingsecret decryption key KM1 unique to memory card 110, and license key Kcand reproduction circuit control information AC2 required for areproduction process are output on data bus BS4 (step S216).

License key Kc and reproduction circuit control information AC2 outputare transmitted via a contact Pd of switch 1442 to encryption unit 1406,which in turn encrypts license key Kc and reproduction circuit controlinformation AC2 received on data bus BS4, with session key Ks3 receivedfrom decryption unit 1412 via contact Pd of switch 1442, and outputsencrypted data {Kc//AC2}Ks3 on data bus BS3 (step S217).

The encrypted data {Kc//AC2}Ks3 output on data bus BS3 is transmittedvia memory interface 1200 to cellular phone 100.

Encrypted data {Kc//AC2}Ks3 received by cellular phone 100 via memoryinterface 1200 is transmitted on data bus BS2 and decrypted bydecryption unit 1212 and license key Kc and reproduction circuit controlinformation AC2 are accepted (step S218). Decryption unit 1212 transmitslicense key Kc to decryption unit 1214 and outputs reproduction circuitcontrol information AC2 onto data bus BS2.

Controller 1106 accepts reproduction circuit control information AC2 ondata bus BS2 and confirms whether reproduction is allowed (step S219).

If at step S219 the control determines from reproduction circuit controlinformation AC2 that reproduction is disallowed, the reproductionoperation ends.

If at step S219 controller 1106 determines that reproduction is allowed,controller 1106 issues a request to memory card 110 via memory interface1200 to provide encrypted content data {Data}Kc. Then in memory card 110controller 1420 obtains encrypted content data {Data}Kc from memory 1415and outputs encrypted content data {Data}Kc to memory interface 1200 ondata bus BS3 and via terminal 1201 (step S220).

In cellular phone 100 controller 1106 obtains encrypted content data{Data}Kc via memory interface 1200 and feeds encrypted content data{Data}Kc on data bus BS2 to decryption unit 1214. Decryption unit 1214decrypts encrypted content data {Data}Kc with license key Kc output fromdecryption unit 1212 and thus obtains content data Data (step S211).

The decrypted content data Data is output to music reproduction unit1216. Music reproduction unit 1216 reproduces the content data and DAconverter 1218 converts a digital signal to an analog signal for outputto terminal 1220. Then switch 1222 selects terminal 1220 and the musicdata is output to headphone 130 via terminal 1224 and thus reproduced(step S222). Thus the reproduction operation completes.

User 1 of cellular phone 100 can uses cellular phone 100 to receiveencrypted content data {Data}Kc and license key Kc distributed fromdistribution server 30, and use license key Kc to decrypt and thusreproduce encrypted content data {Data}Kc.

Note that cellular phone 100 of user 1 can also have cellular phone 100of user 2 transfer encrypted content data {Data}Kc (and it can thusreceive the data). In this case, when user 2 confirms that license keyKc decrypting encrypted content data {Data}Kc received is not recordedin memory card 110, user 2 requests distribution server 30 to distributelicense key Kc.

Similarly, cellular phone 100 of user 2 can receive the license key fromdistribution server 30 and the license key can be used to encrypt andreproduce encrypted content data.

Reference will now be made to FIG. 13 to more specifically describe arelationship between opened and closed positions of the casing ofcellular phone 100 in the form of the shell in the first embodiment, anda download process.

Initially, cellular phone 100 has the casing in an opened position andit also has a standby status (step S1000). In this condition, thecontrol determines whether a download process is designated to recordrequested content data in memory card 110 (step S1002). If so and theauthenticity of the request for the distribution is also confirmed,cellular phone 100 is conferred a download or call status on (stepS1004). If for example a reproduction mode or any other process modethan the download process is designated then the mode as designated isset (step S1006).

The amount of data distributed or the like is monitored by controller1106 to determine whether the downloading has completed (step S1008).

If the control determines that the downloading has completed, cellularphone 100 is again conferred the standby status on (step S1000).

If the control determines that the downloading still continues,detection unit 1117 determines whether the casing of cellular phone 100has been closed (step S1010).

If not then the download status is held (step S1004).

If the casing is closed, the cellular phone is conferred a status on tocontinue a download process until the current downloading completes(step S1012). With this status, power supply control unit 1116 continuesto supply each circuit with a power supply voltage required for thecall.

Then the amount of data distributed or the like is monitored bycontroller 1106 to determine whether the downloading has completed (stepS1014).

If not then the cellular phone is conferred the aforementioned status onto wait for the current downloading to complete (step S1012).

If the control determines that the downloading has completed, the callis disconnected (step S1016).

Then the cellular phone is conferred a standby status on with the casingclosed, when power supply control unit 1116 controls cellular phone 100to enter a low power consumption mode, a mode minimizing powerconsumption.

Reference will now be made to FIG. 14 to more specifically describe arelationship between the opened and closed positions of the casing ofcellular phone 100 in the form of the shell in the first embodiment, anda data reproduction process. Memory card 110 is assumed to have recordedtherein content data to be reproduced.

Initially, cellular phone 100 has the casing in an opened position andit also has a standby status (step S100). In this condition, the controldetermines whether a reproduction mode is designated to reproduce thecontent data (step S1102). If so then cellular phone 100 is conferred areproduction status on to reproduce content data designated (stepS1104). If a process mode other than the reproduction mode isdesignated, such as a download process, then the mode as designated isset (step S1106).

Once a reproduction process starts, controller 1106 determines whetherthe reproduction has completed (step S1108).

If so then the cellular phone is again conferred the standby status on(step S1100).

If the reproduction still continues, detection unit 1117 determineswhether the casing of cellular phone 100 has been closed (step S1110).

If not then the reproduction status is held (step S1104).

If the casing has been closed, then the cellular phone is conferred astatus on to continue the reproduction process until the content data iscompletely reproduced (step S1112). With this status, power supplycontrol unit 1116 continues to supply each circuit with a power supplyvoltage required for the reproduction process.

Then controller 1106 determines whether the reproduction has completed(step S1114).

If not then the cellular phone is conferred the aforementioned status onto continue the reproduction process until the content data iscompletely reproduced (step S1112).

If the control determines that the reproduction has completed, then thecellular phone is conferred a standby status on with the casing closed,when power supply control unit 1116 controls cellular phone 100 to entera low power consumption mode, a mode minimizing power consumption.

In the first embodiment the cellular phone can reproduce encryptedcontent data while the copyright of the data can sufficiently beprotected.

Furthermore if its case in the form of the shell is closed while data isbeing downloaded, cellular phone 100 can complete downloading the data.In particular, it is no longer necessary to leave the cellular phonewith its casing open to download a large amount of data such as musiccontent. Furthermore, if its casing is closed while music is beingreproduced, cellular phone 100 still can continue to reproduce themusic.

Second Embodiment

A second embodiment describes another exemplary configuration ofcellular phone 100 of the first embodiment. Note that the presentembodiment employs a data distribution system, license server and memorycard having the configuration as has been described in the firstembodiment.

The second embodiment provides a cellular phone having a circuitseparated into communication process system circuitry and a reproductionsystem. More specifically, a communication function is provided to amain body of the cellular phone, configured as shown in FIG. 15, whichwill be referred to as a main body 100 a of the cellular phone.Separated from main body 100 a, a music reproduction module 120 isprovided, as shown in FIG. 16. Controller 1106 is separated into a mainCPU 1106 a of main body 100 a and a sub CPU 1230 of audio reproductionmodule 120.

Main body 100 a and audio reproduction module 120 are both incorporatedinto the casing in the form of the shell as described above. They may beseparated as of a remote control type and in that case, for example asshown in FIG. 16, a remote control unit 1222 may be employed, with a keyoperation unit 1224 and a display 1226 included.

With reference to FIG. 15, main body 100 a includes an antenna 1102, atransmission and reception unit 1104, a data bus BS2, a main CPU 1106 acontrolling a circuit operation of main body 100 a via data bus BS2, akey operation unit 1108, a display 1100, an audio reproduction unit1112, a DA converter 1113, and a terminal 1114 receiving an output ofthe DA converter.

Main body 100 a also includes a power supply control unit 1116, adetection unit 1117 detecting whether the shell is open or closed, and aserial interface 1118. Via serial interface 1118 main body 100 acommunicates data with audio reproduction module 120.

As has been described previously, detection unit 1117 detects whetherthe casing in the form of the shell enclosing main body 100 a and audioreproduction module 120 has an opened position or a closed position.Detection unit 1117 outputs a result which is in turn transferred tomain CPU 1106 a on data bus BS2. Power supply control unit 1116 iscontrolled by main CPU 1106 a to supply main body 100 a and/or audioreproduction module 120 with an operating power supply.

With reference to FIG. 16, audio reproduction module 120 includes anauthentication data hold unit 1202, a Kp1 hold unit 1204, decryptionunits 1206, 1212 and 1214, an encryption unit 1208, a session keygeneration unit 1210, a music reproduction unit 1216, a DA converter1218, a connection terminal 1220, and a serial interface 1228.

Audio reproduction module 120 also includes a data bus BS3, a sub CPU1230 controlling an operation of audio reproduction module 120, a memorycard 110, and a memory interface 1200 arranged between memory card 110and data bus BS3. Via serial interface 1228, audio reproduction module120 communicates data with cellular phone 100 a.

The opened and closed positions of the casing in the form of the shelland a process effected to download content data, have the relationshipas has been described in the first embodiment. Furthermore, the openedand closed positions of the casing and a process effected to reproducecontent data has the relationship as has been described in the firstembodiment.

Thus the second embodiment can also provide a cellular phone, having acommunication process system and a reproduction process system separatedfrom each other, that is as effective as the first embodiment.

Third Embodiment

Reference will now be made to FIGS. 17 and 18 to describe a thirdembodiment of the present invention. Cellular phone 100 can receive newencrypted content data {Data}Kc from memory card 110 attached to anothercellular phone 100. In doing so, it issues a request to distributionserver 30 to receive license key Kc corresponding to encrypted contentdata {Data}Kc. In the third embodiment, cellular phone 100 receivesencrypted content data {Data}Kc for example distributed on the Internetvia a computer and records the received encrypted content data in memorycard 110 and requests distribution server 30 to distribute license keyKc corresponding to the encrypted content data, as will exemplarily bedescribed hereinafter.

With reference to FIG. 17, encrypted content data {Data}Kc isdistributed via a computer 140, as will now be described. Cellular phone100 allows memory card 110 to be detachably attached thereto and it hasheadphone 130 connected thereto for reproducing music. Furthermore,cellular phone 100 is connected to computer 140 via a communicationcable 145.

Computer 140 includes a hard disk 141, a controller 142, and an externalinterface 143. Hard disk 141 is connected to controller 142 via data busBS5. Controller 142 includes a license protection module 144.

Hard disk 141 stores via data bus BS5 encrypted content data {Data}Kcdistributed on the Internet to computer 140. When controller 142receives a request from user 1 of cellular phone 100 via communicationcable 145 and external interface 143 to transmit encrypted content data{Data}Kc, controller 142 reads encrypted content data {Data}Kc from harddisk 141 and outputs the data externally via external interface 143.

External interface 143 inputs to controller 142 a signal input tocomputer 140 from cellular phone 100 via communication cable 145 and italso externally outputs a signal received from controller 142.

License protection module 144 has a configuration identical to that ofthe FIG. 6 data processing unit 310 and, to transmit encrypted contentdata {Data}Kc to memory card 110 attached to cellular phone 100,communicates public encryption keys, session keys and the like withcellular phone 100 and memory card 110, as has been describedpreviously, while protecting and thus transmitting encrypted contentdata {Data}Kc to memory card 110.

On the Internet from distribution server 30 to computer 140 encryptedcontent data {Data}Kc is distributed and stored at hard disk 141 incomputer 140 via data bus BS5.

When user 1 of cellular phone 100 operates key operation unit 1108 toinput a request for transmission, the request for transmission is inputto controller 142 via communication cable 145 and external interface143. When controller 142 receives the request for transmission,controller 142 reads requested, encrypted content data {Data}Kc fromhard disk 141 via data bus BS5 and inputs it to license protectionmodule 144.

As has been described previously, license protection module 144communicates public encryption keys, session keys and the like withmemory card 110 via communication cable 145 and transmits encryptedcontent data {Data}Kc to memory card 110.

After the transmission, user 1 of cellular phone 100 have distributionserver 30 to distribute license key Kc for encrypted content data{Data}Kc, as has been described previously, and reproduces encryptedcontent data {Data}Kc.

Furthermore, computer 140 is not limited to receiving encrypted contentdata {Data}Kc distributed on the Internet, and it may also readencrypted content data {Data}Kc recorded on a CD-ROM set in a CD-ROMdrive (not shown) connected to computer 140 and transmit the data tomemory card 110. Furthermore, encrypted content data {Data}Kc recordedon the CD-ROM may once be stored on hard disk 141.

Furthermore, computer 140 may produce encrypted content data {Data}Kc byCD-ripping. “Ripping” means converting music data obtained from a musicCD, so as to be reproducible by a music reproduction module. Initially,a license is produced for music data obtained. Then the obtained musicdata is converted to content data reproducible by music reproductionunit 1216 and it is then encrypted to be decryptable with a license keyincluded in the produced license. The license produced to decryptencrypted content data obtained by ripping, is managed to benon-replicable. Thus, the CD-ripping, corresponding to a primaryreplication from a music CD, is a legal activity protecting a copyrightby encrypting content and providing a non-replicable license including alicense key corresponding to a key used to decrypt the encryptedcontent.

If a CD is used, encrypted content data {Data}Kc obtained from a musicCD and generated may once be recorded on hard disk 141 and thereaftertransmitted to memory card 110 or it may not be recorded on hard disk141 and instead directly be transmitted to memory card 110.

Encrypted content data {Data}Kc may be recorded directly in memory card110 attached to computer 140, as shown in FIG. 18. In this case,controller 142 of computer 140 records encrypted content data directlyin memory card 110 via license protection module 144.

In FIG. 18, computer 140 also obtains encrypted content data {Data}Kc bya method identical to that shown in FIG. 17.

Cellular phone 100 requests distribution server 30 to distribute licensekey Kc corresponding to encrypted content data {Data}Kc additionallyreceived and it reproduces the additionally received encrypted contentdata {Data}Kc, as represented in the flow charts referred to in thefirst embodiment.

In the third embodiment when a cellular phone receives additionalencrypted content data on the Internet, by CD-ripping or the like, itautomatically issues a request to a distribution server to receive alicense key decrypting the encrypted content data. As such, if a user ofthe cellular phone receives only encrypted content data distributed forexample on the Internet it can reproduce the encrypted content data.

Note that while in the above description a cellular phone in the form ofa shell is referred to by way of example, the present invention is notlimited thereto and it is also applicable to any data terminal devicesthat do not receive power supply when the flap is flipped closed.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the terms ofthe appended claims.

1. A data terminal device accommodated in a casing in a form of a shell,downloading from a distribution server encrypted content data and alicense key decrypting said encrypted content data, and reproducing saidencrypted content data, comprising: a communication unit externallyeffecting a communication; a data recording device recording saidencrypted content data and said license key therein, and receivingauthentication data and outputting said license key only when saidauthentication data is authenticated; an interface controlling datacommunication; a control unit; a detection unit detecting whether saidcasing is open/closed; and a power supply control unit controllingwhether to supply various components with power, wherein when saiddetection unit detects that said casing is closed after download of saidencrypted content data is started, said power supply control unitcontrols supplying power required for a call to complete downloadingsaid encrypted content data.
 2. The data terminal device of claim 1,wherein when the data terminal device with said casing closed completesdownloading said encrypted content data, said power supply control unitfor example stops supplying said power and controls a standby modefunction of said various components internal to the data terminal deviceto shift the data terminal device to a low power consumption mode.
 3. Adata terminal device accommodated in a casing in a form of a shell,downloading from a distribution server encrypted content data and alicense key decrypting said encrypted content data, and reproducing saidencrypted content data, comprising: a communication unit externallyeffecting a communication; a data recording device recording saidencrypted content data and said license key therein, and receivingauthentication data and outputting said license key only when saidauthentication data is authenticated; a reproduction unit reproducingsaid encrypted content data recorded in said data recording device; aninterface controlling data communication; a control unit; a detectionunit detecting whether said casing is open/closed; and a power supplycontrol unit controlling whether to supply various components withpower, wherein when said detection unit detects that said casing isclosed after reproduction of said encrypted content data is started,said power supply control unit controls supplying power required for areproduction process to complete reproducing said encrypted contentdata.
 4. The data terminal device of claim 3, wherein when the dataterminal device with said casing closed completes reproducing saidencrypted content data, said power supply control unit for example stopssupplying said power and controls a standby mode function of saidvarious components internal to the data terminal device to shift thedata terminal device to a low power consumption mode.
 5. A data terminaldevice accommodated in a casing in a form of a shell, downloading from adistribution server encrypted content data and a license key decryptingsaid encrypted content data, recording said encrypted content data andsaid license key in a data recording device, and reproducing saidencrypted content data via said data recording device, comprising: acommunication unit externally effecting a communication; an interfacecontrolling data communication; a control unit; a detection unitdetecting whether said casing is open/closed; and a power supply controlunit controlling whether to supply various components with power,wherein when said detection unit detects that said casing is closedafter download of said encrypted content data is started, said powersupply control unit controls supplying power required for a call tocomplete downloading said encrypted content data.
 6. The data terminaldevice of claim 5, wherein when the data terminal device with saidcasing closed completes downloading said encrypted content data, saidpower supply control unit for example stops supplying said power andcontrols a standby mode function of said various components internal tothe data terminal device to shift the data terminal device to a lowpower consumption mode.
 7. A data terminal device accommodated in acasing in a form of a shell, downloading from a distribution serverencrypted content data and a license key decrypting said encryptedcontent data, recording said encrypted content data and said license keyin a data recording device, and reproducing said encrypted content datavia said data recording device, comprising: a communication unitexternally effecting a communication; an interface controlling datacommunication; a control unit; a reproduction unit reproducing saidencrypted content data recorded in said data recording device; adetection unit detecting whether said casing is open/closed; and a powersupply control unit controlling whether to supply various componentswith power, wherein when said detection unit detects that said casing isclosed after reproduction of said encrypted content data is started,said power supply control unit controls supplying power required for areproduction process to complete reproducing said encrypted contentdata.
 8. The data terminal device of claim 7, wherein when the dataterminal device with said casing closed completes reproducing saidencrypted content data, said power supply control unit for example stopssupplying said power and controls a standby mode function of saidvarious components internal to the data terminal device to shift thedata terminal device to a low power consumption mode.